There are two ways to represent statements:
1) Intensionally - This is the way RDF M&S does it with the reification
quad. In that quad we specify the criteria which identifies a statement.
In other words we say that we are talking about any statement which
satisfies the properties subject=s, property=p, and object=o. Such an
intensional representation of a statement refers to the ideal triple, but
not to its context of utterance.
2) Extensionally - Such a method would need to be able to point out any
statement in its context of utterance.
Production 6.12 of M&S syntax [1] provides a method of designating an idAttr
for any statement. With a little bit of cooperation from the RDF WG we
could use this technique to represent statements extensionally.
[1] http://www.w3.org/TR/REC-rdf-syntax/#grammar
<description about=Sky>
<is id=ID1234 resource=Blue />
</description>
<description about=John>
<says resource=ID1234 />
</description>
Seth Russell